//! \file PathSearch.h
//! \brief Defines the <code>fullsail_ai::algorithms::PathSearch</code> class interface.
//! \author Cromwell D. Enage
#ifndef _FULLSAIL_AI_PATH_PLANNER_ALGORITHMS_PATH_SEARCH_H_
#define _FULLSAIL_AI_PATH_PLANNER_ALGORITHMS_PATH_SEARCH_H_

#include "../Core/Tile.h"
#include "../Core/TileMap.h"
#include "../Core/PriorityQueue.h"
#include <vector>
#include <queue>
#include <map>

namespace fullsail_ai { namespace algorithms {

	class PathSearch
	{
	private:
		struct PlannerNode
		{
			PlannerNode*	m_pParent;
			Tile*			m_pTile;
			double			m_dDist;

			PlannerNode(Tile* pTile = NULL, PlannerNode* pParent = NULL, Tile* pGoal = NULL) : m_pTile(pTile), m_pParent(pParent)
			{
				if(pTile)
				{
					this->m_dDist = ((pGoal->getXCoordinate() - pTile->getXCoordinate())*(pGoal->getXCoordinate() - pTile->getXCoordinate())) + 
						((pGoal->getYCoordinate() - pTile->getYCoordinate())*(pGoal->getYCoordinate() - pTile->getYCoordinate()));
				}
				else
					this->m_dDist = 0;
			}
			~PlannerNode(void)
			{
			}
		};

		bool	AreAdjacent(Tile const* lhs, Tile const* rhs);

		static bool Distance( PlannerNode* const& p1,  PlannerNode* const& p2);
		 
		
		TileMap*								m_pTileMap;
		Tile*									m_pGoal;
		PriorityQueue<PlannerNode*>				m_qList;
		std::map<Tile const*, PlannerNode*>		m_mHash;

		bool m_bIsDone;
	public:
		//! \brief Default constructor.
		PathSearch();

		//! \brief Destructor.
		~PathSearch();

		//! \brief Sets the tile map.
		//!
		//! Invoked when the user opens a tile map file.
		//!
		//! \param   _tileMap  the data structure that this algorithm will use
		//!                    to access each tile's location and weight data.
		void initialize(TileMap* _tileMap);

		//! \brief Enters and performs the first part of the algorithm.
		//!
		//! Invoked when the user presses one of the play buttons.
		//!
		//! \param   startRow         the row where the start tile is located.
		//! \param   startColumn      the column where the start tile is located.
		//! \param   goalRow          the row where the goal tile is located.
		//! \param   goalColumn       the column where the goal tile is located.
		void enter(int startRow, int startColumn, int goalRow, int goalColumn);

		//! \brief Returns <code>true</code> if and only if no nodes are left open.
		//!
		//! \return  <code>true</code> if no nodes are left open, <code>false</code> otherwise.
		bool isDone() const;

		//! \brief Performs the main part of the algorithm until the specified time has elapsed or
		//! no nodes are left open.
		void update(long timeslice);

		//! \brief Returns an unmodifiable view of the solution path found by this algorithm.
		std::vector<Tile const*> const getSolution() const;

		//! \brief Resets the algorithm.
		void exit();

		//! \brief Uninitializes the algorithm before the tile map is unloaded.
		void shutdown();
	};
}}  // namespace fullsail_ai::algorithms

#endif  // _FULLSAIL_AI_PATH_PLANNER_ALGORITHMS_PATH_SEARCH_H_

